1. Field
The invention relates to illuminating means for use in examining body cavities and for use with medical instruments for medical examination purposes, such as, but not limited to, a vaginal speculum.
2. State of the Art
Various illuminating means have been employed in the past to illuminate cavities within the human body to facilitate examination thereof or the performance of medical procedures therein. Among these are various light-conductive specula. For example, there is a device disclosed by Moore et al. in U.S. Pat. No. 3,716,047. Although the speculum disclosed by Moore et al. is designed to be made at a cost low enough to warrant discarding after use, it is to be used in conjunction with a nondisposable light source that is not a low-cost item and requires the use of such light source with a speculum specially designed for use therewith. That is, it is not adaptable to a variety of specula. Likewise, the specula disclosed by McDonald in U.S. Pat. No. 3,762,400 and by VanDerBel in U.S. Pat. No. 4,597,383 use non-disposable light sources that are not adaptable to the variety of specula most commonly employed by physicians.
Furthermore, these patented illumination devices and other illumination devices on the market employ projected, directional light. Some commercially available specula have their lighting means disposed on the lower blades of the specula where a heavy discharge, e.g., a vaginal discharge, can pool and obscure the light source. It is desirable to have an illuminating device that can be applied to and employed with the variety of specula and other medical instruments commonly used by medical practitioners and one that uses a global light source instead of projected, directional light. If used with a vaginal speculum, it is further desirable that the light source be disposed adjacent to the upper blade thereof to avoid being obscured by pooled body fluids.
The lighting device of the invention is adapted particularly for examination of human and other animal body cavities and includes a non-directional, global light source at the end of a flexible and preferably malleable arm that radiates light of brightness sufficient for the examination concerned while the light source remains below a temperature that will damage living tissue. In addition, the lighting device has a light source and extension arm configured to be of relatively small diameter so as to easily be positioned in or along a medical examination device such as a vaginal speculum or fed into a cavity through a tube such as an intubation tube or paralleling a retractor in open wounds.
The device of the invention includes a nondirectional, global light source mounted at the end of a malleable arm which is connected to a case housing a source of power, such as a battery, so that power can be connected to the light source through the arm when illumination of the light source is desired. For most applications, the arm and light source at the end thereof should have a diameter of no more than about three millimeters so that it can easily fit along or through various medical devices such as along an arm of a vaginal speculum without interfering with the viewing area or may be inserted through a tube such as a intubation tube. Further, since the light source may come in contact with or be positioned in close proximity to human or other animal tissue, it is important that the temperature of the light source be limited to a temperature below that which will damage living tissue. Thus, it is preferred that the temperature of the light source be controlled to remain below about 42xc2x0 C. This can be done by controlling the power supplied to the light source as by inserting a resistor in series between the light source and source of power, and if desired, in addition providing a transparent sheath over the light source. The light source needs to provide enough light for the examination concerned, so if a body cavity examination is being performed, enough light to illuminate the interior of the cavity, or if a dental exam or location determination such as an intubation tube placement is being performed, enough light to shine through a tooth or through the chest and skin. A light output of about 75 foot candles at one-half inch and about 50 foot candles at one inch from the source has been found satisfactory. The light source may conveniently take the form of an incandescent quartz-halogen light of the type used in xe2x80x9cmag lightxe2x80x9d flashlights.
A switch may be provided between the light source and power supply for connecting power when desired to illuminate the light source, or the connection of the arm to the light source can be configured so that when securely connected, such as by screwing the base of the arm tightly into a power source case, the light source is connected. In such case, the light source is disconnected by partially unscrewing the arm from the power source case.
For many applications, the power source case will be removably secured to a medical instrument, such as a vaginal speculum, so that the device, including the arm and light source, are secured to and become part of the instrument. For use with a vaginal speculum, the invention includes a special clip which is secured to the speculum and which removably holds the power source case, and in turn the arm and light source, to the speculum so that the doctor can use the speculum in normal manner, except that the lighting device of the invention is provided as a part thereof and aids in the examination.
While it is currently preferred that the arm be malleable throughout its length, for some applications, the arm may include a rigid portion extending from the power source case with a malleable portion holding the light source at its distal end. Thus, the device may be attached to a medical instrument as part of a light-providing instrument and still be subject to deformation suitable to the task at hand as may be required or desired by the physician, surgeon, or other medical practitioner using the device. For use with a speculum or similar instrument, the rigid portion of the arm is formed to extend around the viewing channel of the instrument, thus saving the physician the step of forming this portion of the arm. The malleable portion is bent to extend along a blade of the speculum to locate the global light source deep within the cavity to be illuminated and out of the way of the physicians view and any pooled body fluids. Having a global light source located deep within a cavity provides illumination far superior to that of the projected, directional light sources of the prior art.
The entire device can be constructed to be moisture resistant and, thus, easily sterilized, unlike some prior art illumination devices. However, to enable the reuse of the lighting device without sterilization, the malleable portion of the arm can be provided with an elongate, flat, disposable covering or sheath having elongate top and bottom walls attached together along the sides and distal ends of such walls, leaving an opening at the proximal end of the covering for the insertion therein of the light source and arm. At least the distal end of such covering is transparent. Advantageously, the covering has a strip of adhesive along an outside wall for removably securing the covering to a blade of the speculum or to other instruments. It is further advantageous to provide the covering with a lip extending from the bottom wall at the opening to facilitate insertion of the malleable portion of the arm.